Effect of carbon black concentration on electrical conductivity of epoxy resin–carbon black–silica nanocomposites
This work presents an insight into the conductivity-carbon black (CB) concentration relationship of nanocomposites. High conductivity is observed above 14% CB loading (% on mass of epoxy resin), indicating the generation of conductive networks throughout the nanocomposites. Observation of the relationship between the natural logarithm of conductivity values versus CB loading shows a remarkable increase in conductivity when the CB loading increases from 19 to 24%. In this region (percolation) a relatively small increase in CB loading produces a large increase in conductivity. When the quantity of CB is low (<14%), the resistivity of the nanocomposite is only slightly different from that of the base polymer; further increase in CB loading beyond the critical concentration region (>24%) causes marginal change in conductivity. The uniformity of the nanocomposites is evidenced by both microstructure (Si-mapping) and macro-property (resistance versus distance relationship) analyses.
KeywordsPercolation Threshold Epoxy Resin Polymer Conductive Network Volume Resistivity Carbon Black Concentration
The authors would like to thank The UK Government (Overseas Research Scholarship Awards Scheme) and The University of Leeds (Tetley and Lupton Scholarships) for the provision of a PhD scholarship to one of us (Wei Zhang).
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